However they have not made progress on plans for a European financial transactions tax, Merkel acknowledged. Britain opposes such a tax, fearing it could disadvantage London as a global financial center.Cameron called for the deal reached at a summit in Europe on October 27 to be implemented as soon as possible.The plan includes a series of measures to address the crisis, including debt relief for Greece, new capital requirements for banks and plans to build a financial "firewall" around vulnerable euro area economies."A strong, successful and stable eurozone is in all our interests," Cameron said."We need this crisis to be resolved. Britain, like Germany, has a big national interest in that happening."